A spring with spring constant $k$ is extended from $x=0$ to $x={x}_{1}$. The work done will be

Two springs have their force constant as $k_1$ and $k_2( k_1 > k_2)$& ;When they are stretched by the same force 

নিচের লেখচিত্রটিতে একটি স্প্রিং-এ প্রযুক্ত বলের সাথে দৈর্ঘ্য বৃদ্ধির পরিবর্তন দেখানো হয়েছে। 

স্প্রিংটির দৈর্ঘ্য বৃদ্ধি 3cm হলে স্প্রিং-এ সঞ্চিত শক্তির পরিমাণ কত ?

A simple pendulum has a string of length $l$ and bob of mass $m$. When the bob is at its lower position, it is given the maximum horizontal speed necessary for it to move in a circular path about the point of suspension. The tension in the string at the lowest position of the bob is

A spring of natural length $l$ is compressed vertically downward against the floor so that its compressed length becomes $\displaystyle\frac{l}{2}$. On releasing, the spring attains it's natural length. If $k$ is the stiffness constant of the spring, then the work done by the spring on the floor is